Today, as the 800V high-voltage platform becomes the mainstream of new energy vehicles, the limitations of traditional PET blue film as a battery cell insulation material are becoming increasingly prominent: the bonding strength of its pressure-sensitive adhesive layer is only 0.5~2MPa, and it is easy to cause cohesive failure under vibration and impact, resulting in a sharp increase in the risk of insulation failure between battery cells. In response to this pain point, Shenzhen U-Sunny launched the U-9103 UV-curing insulation coating, which uses innovative cationic curing technology to provide a new insulation protection solution with higher reliability and stronger adhesion for power batteries.
1. Why is PET blue film upgraded?
Traditional blue film is made of PET substrate composite pressure-sensitive adhesive (PSA). Although it has basic insulation performance, it exposes two key defects under high-voltage platforms:
Insufficient bonding strength: The shear strength of the blue film PSA adhesive layer is only 0.5~2MPa. When the battery cells are directly bonded into groups by structural adhesive, the blue film is easy to peel off from the metal shell or the adhesive layer is cohesively damaged, resulting in failure of the insulation barrier;
Insufficient high-voltage tolerance: The risk of arc breakdown between battery cells under the 800V architecture is significantly increased, and the edge coverage and long-term pressure resistance of the blue film are difficult to meet the safety requirements of the new generation of batteries.
The practice of BMW, Volkswagen and other automakers turning to UV insulation coatings confirms the industry trend-in 2023, the BMW Leipzig plant will put into production the first battery cell UV spraying line, and the acrylic system coating will completely replace the blue film.
2. Core technical advantages of U-9103 UV insulation coating
Shenzhen U-Sunny U-9103 is specially designed for power battery insulation upgrade, integrating cationic curing technology and functional resin system to achieve three major breakthroughs:
(I) High adhesion and impact resistance
Through molecular structure optimization, U-9103 forms a chemical bond with the metal shell after curing, and the shear strength is significantly higher than that of traditional blue film and powder coating. In the ASTM D1002 test of Parker Lord Laboratory, the failure mode of similar UV coatings is cohesive failure of the coating (non-interfacial peeling), which confirms its bonding reliability;
Withstands -40°C~100°C thermal shock and 85°C/85%RH aging to ensure the integrity of the insulation layer of the battery pack throughout its life cycle.
(II) Efficient production compatibility
Second-level curing: Under 1900mW/c² UV light intensity, 50~70μm coating can be cured in a few seconds, without the multiple processes required for blue film coating or 30 minutes of baking for powder coating;
Seamless adaptation to automation: Supports robot spraying, and 6-sided battery cell insulation treatment can be completed within 2 minutes, significantly improving production line efficiency.
(III) Insulation guarantee under high voltage environment
Dielectric strength ≥80kV/mm, excellent edge coverage, effectively preventing corona discharge and creepage under 800V platform;
100% solid formula, no solvent volatilization (zero VOCs), avoiding environmental pollution and pore penetration risks during battery production.
3. Typical application scenarios: from battery cells to battery packs
U-9103 has been successfully applied to power battery systems in multiple fields:
Square/cylindrical battery cell insulation coating: directly sprayed on the battery cell shell, replacing blue film tape, improving integration and lightweight level;
Module end plate and bracket protection: the coating is resistant to electrolyte corrosion (passed ISO 16750-5 test), extending the life of structural parts;
CTP/CTC battery pack structural bonding interface: as a transition layer between structural adhesive and metal shell, it enhances bonding reliability and reduces the risk of cracking under vibration conditions.
4. Why choose U-Sunny U-9103?
Localized technical support: Shenzhen U-Sunny provides full-process support from formula debugging, spraying parameter optimization to production line adaptation, and completes process verification within 7 working days;
Green manufacturing compatible: Comply with GB 33372-2020 low VOCs standard, and adapt to industrial wastewater treatment system;
Cost controllable upgrade: The unit cell coating cost is close to traditional blue film, and the equipment investment recovery period is <12 months (based on 1 million units/year production capacity).
5. Towards a future of high-safety batteries
As companies accelerate the industrialization of UV coating, the technical iteration of insulating materials has become the core link in the safe evolution of power batteries. Shenzhen U-Sunny U-9103 achieves a balance between bonding strength, production efficiency and high-voltage protection through material innovation, providing a reliable insulation solution for the 800V era.